Manfro was injured in practice on Tuesday and taken off in a cart.
"That put a damper on practice,” UCLA coach Jim Mora told the Los Angeles Times. “Everyone was pretty shook up. We were having a good day. It kind of changed the mood.”
Manfro only had two carries for minus-5 yards and caught one pass for minus-4 yards in UCLA's 28-20 victory over Virginia last Saturday.
UCLA's rushing game averaged only 3.3 yards per carry against Virginia, prompting offensive line coach Adrian Klemm to rip into the team's performance.
Freshman Nate Starks is likely to take Manfro's spot in the offense in Saturday's game against Memphis.
- Scooby Axson